Using just the slug without an ID is the most descriptive* and probably most SEO-friendly. The downside is that we need save the slug and any historical ones in order to retrieve the related question. In Rails this is pretty straightforward though using the FriendlyId gem.
(* the ID does however suggest how old the question is. A lower ID means an older question. I'm not sure if that's an advantage or disadvantage. Probably doesn't matter that much. )
Using just the slug without an ID is the most descriptive* and probably most SEO-friendly. The downside is that we need save the slug and any historical ones in order to retrieve the related question. In Rails this is pretty straightforward though using the FriendlyId gem.
(* the ID does however suggest how old the question is. A lower ID means an older question. I'm not sure if that's an advantage or disadvantage. Probably doesn't matter that much. )